Identifying potentially active faults in mainland British Columbia using available datasets

许多发达国家在危险评估中考虑浅层地壳断层，因为有证据表明这些断层要么是活跃的，要么是有能力的。然而，在不列颠哥伦比亚省，迄今为止，只有一个这样的地壳断层被包括在我们的国家地震危险模型中。将不列颠哥伦比亚省西南部大陆视为没有浅层地壳断层，既与我们对俯冲带应力如何传递给上地壳的构造理解不一致，也与邻近的美国地质调查局（US）的评估不一致，后者包括至少延伸到边界的众多断层，可能还会进一步向北延伸。因此，在人口密集的低陆平原地区，活动断层的威胁及其次生危害在很大程度上仍然未知。目前牵头编制《国家地震风险模型情景地震目录》（2020年11月发布）。这项工作需要了解加拿大各地的断层，以及了解这些断层如何影响建筑环境和社区。现在，我们希望将这项工作扩展到尚未映射的断层。我们建议利用现有数据在南部海岸山区寻找可能的活动断层，该地区从乔治亚海峡向东延伸到曼宁公园，从加拿大/美国边境北部延伸到彭伯顿冰原，该地区约有280万人口，资产约占加拿大国内生产总值的41%。该研究项目将通过以下方式提高我们对大陆地壳断层的认识：[1]利用最近收集的数字高程数据，根据地貌表达直观地识别潜在的活动断层，[2]利用新开发的构造块体模型模拟潜在的应力积累，[3]利用地震风险评估定量评估断裂的潜在物理影响和社会经济后果，[4]进入油田，记录未来断层近期位移的地质证据。例如火山岩脉偏移，以及[5]利用大地测量和其他地球物理数据来表征当前断层的变形和活动速率。通过我们将创建的地震情景目录（Fault Database）和RiskProfiler.ca（一个用户友好的网络平台），公民、科学家、城市规划者和政策制定者将能够自由获取他们制定降低风险战略所需的证据。我们希望“完成绘制”目前只存在于美国边境的断层，并通过古地震沟、直升机进入的全球导航卫星系统（GNSS）或高分辨率光探测和测距（LiDAR）来确定适合更详细和昂贵研究的断层。该项目将为科学界做出贡献，允许一名年轻的女性PI培训两名新科学家，这些科学家将从目前在地球科学领域代表性不足的群体中选出。

Many developed countries consider shallow, crustal faults in their hazard assessments, where there is evidence that faults are either active or capable. In British Columbia (BC), however, only one such crustal fault has been included in our national seismic hazard model to date. Treating the southwest BC mainland as if devoid of shallow, crustal faults is at odds with both our tectonic understanding of how subduction zone stresses are imparted to the upper crust, and the neighbouring United States (US) Geological Survey assessment which includes numerous faults extending at least to the border and presumably further north. Thus, the threat of active faults, and their secondary hazards, in the densely populated Lower Mainland region remains largely unknown. Currently, I lead the development of the National Seismic Risk Model Scenario Earthquake Catalogue (release in November 2020). This work requires knowledge of faults across Canada as well as an understanding of how those faults impact the built environment and communities. Now, we hope to extend this work to as-yet unmapped faults. We propose to use existing data to hunt for possibly active faults in the southern Coast Mountain region extending from the Strait of Georgia East to Manning Park, and from the Canada/US border North to the Pemberton Icefields - a region home to approximately 2.8 million people and assets valuing roughly 41% of Canada's gross domestic product. This research program will improve our understanding of crustal faults on the mainland by: [1] using recently collected digital elevation data to visually identify potentially active faults based on their geomorphic expression, [2] modelling their potential stress accumulation using a newly developed tectonic block model, [3] quantitatively assessing the potential physical impacts and socioeconomic consequences of ruptures using seismic risk assessment, [4] going into the field to document geologic evidence of recent displacement along prospective faults, such as volcanic dike offsets, and [5] using geodetic and other geophysical data to characterize the current deformation and activity rate of faults. Through the Earthquake Scenario Catalogue, a Fault Database we will create, and RiskProfiler.ca - a user-friendly web platform - citizens, scientists, city planners, and policy makers will be able to freely access the evidence they need to enact risk reduction strategies. We hope to `finish drawing' faults which currently only exist on the US side of the border, and identify faults which are well-suited to more detailed and expensive studies through paleoseismic trenching, campaign Global Navigation Satellite System (GNSS) with helicopter access, or high resolution Light Detection and Ranging (LiDAR). This program will contribute to the scientific community by allowing a young, female PI to train 2 new scientists, to be selected from groups currently under-represented in geosciences.